Better sit down for this one, folks. Dellmus Colvin, also known as the Interstate Strangler, has been behind bars since 2006 after being convicted for the murders of several women. However, after appearing on an episode of the podcast Where the Bodies are Buried, hosted by criminal profiler Phil Chalmers, the 61-year-old American serial killer made a surprising admission and claimed that he killed another woman outside of a truck stop 15 years ago.